利用林窗部分转换技术测定苹果树冠层结构

常规直接测定果树冠层结构几乎是不可能的，目前主要用间接测定的方法。利用林窗部 分转换技术（ＧＦＴＴ）测定三种不同砧木（Ｍ９，ＭＭ１０６，Ｈａｓｈａｂｉ）金冠苹果园的冠层结构，结果表明，不同 砧木苹果树叶面积相差很大，但叶面积指数差异不大。用林窗部分转换技术测定的叶面积与用叶 面积积仪测定的结果差异少于１个叶面积指数，说明这一技术是可行的。此外，两个苹果园（Ｍ９， ＭＭ１０６砧木）用上述两种方法测出的叶面积指数均无差异，又说明林窗部分转换技术测定的叶面 积指数具有相对的准确性。

Studies on the Canopy Structure of Apple Trees Using Gap Fraction Inversion Technique(GFIT)

It is almost impossible to measure the canopy structure of orchard bes using routine direct measurement. At present, canopy structure is primarily measured by indirect method. In this paper, canopy structure was measured by the gap fraction inversion method. Three apple orchards (with M9, MMl06 and Hashabi rootstocks) with different canopy structure were chosen for the study.The results showed that leaf area index (LAI) was not significantly different for each rootstock even though measured leaf area (LA) per tree differed greatly. Results also showed a difference of less than I LAI between the destructive measurements and the gap fraction inversion technique which is reasonable. In addition no significant differences in LAI between the two orchards (M9, MM106) were found in either measurement method indicating good relative accuracy of the gap fraction inversion method.